ИСТИНА

Цель работы - проведение сравнительного структурного и филогенетического анализа пластомов представителей трибы Loteae для изучения эволюции различных линий в пределах трибы.

Despite the relative conservativeness of the plastid genome in flowering plants, its numerous rearrangements, including inversions, expansion, compression and loss of the typical inverted repeat (IR), loss of genes and introns and accumulation of repeats, have been noted in the subfamily Papilionoideae of Leguminosae. The largest number of rearrangements of the plastome was noted in the IRLC clade, which includes the majority of economically important legumes. The tribe Loteae, which unites 16 genera and about 280 plant species of legumes, includes shrubs, shrublets, semi-shrubs, perennial and annual grasses common in Eurasia, Africa, Australia, Oceania, North and South America. The tribe is not included in the IRLC clade, but is located close to it in the phylogenetic tree of legumes. The molecular phylogeny of the tribe Loteae is characterized by partial incongruence of tree topologies constructed by nuclear and plastid markers, which may be the result of reticulation processes and different rates of sequence evolution. The slower evolution of plastid sequences compared to nuclear ones has led to a lack of proper resolution in the relationship between several taxa within Loteae by plastid markers, which can be overcome by analyzing complete sequences of plastids. To date, only three complete plastid genomes of representatives of the tribe belonging to the genus Lotus (L. japonicus and L. corniculatus, close species of the same section) and Coronilla (C. varia=Securigera varia) have been published. There is no data on other genera. However, the analysis of the closest related groups, namely the genera Robinia and Sesbania, showed the presence of rearrangements in their plastid genome, which suggests that a comparative structural and phylogenetic analysis of the plastomes of representatives of the tribe Loteae may be promising for studying the evolution of various lineages within the tribe. The main objectives of the project include: 1. Complete reading and annotation of 10-15 plastid genomes of representatives of large genera of the tribe Loteae (Acmispon, Anthyllis, Coronilla, Hippocrepis, Hosackia and Lotus). For the largest genus of the tribe, Lotus, obtaining plastid genomes for representatives of several sections. 2. Conducting a comparative analysis of the plastomes between the studied genera of the tribe and sections of the genus Lotus and comparing them with data from other sources of information (phylogenetic position of taxa in the phylogeny by nuclear markers, morphological features, geography). 3. Conducting phylogenetic analyses based on a set of several plastid markers for critical groups of species. The material for the study will be live plants grown from seeds in the greenhouse of Moscow State University or collected in natural habitats. Herbarium material is planned to be used as an additional one. To carry out sequencing by NGS methods, it is planned to use a special technique for isolating DNA samples enriched with plastid sequences. The prepared libraries will be sequenced on the Illumina platform (or on another available platform). The data obtained will expand our understanding of the phylogeny of the tribe Loteae and clarify the complex moments of its evolution. Structural analysis of plastid genomes will become the basis for their further functional analysis. The results of the project can be also applied to the analysis of plastid genomes of related plant groups.

2023 год: 1) Будут получены последовательности полных пластидных геномов 6-8 представителей трибы Loteae. 2) Будет собран и получен от коллег новый материал по 5-10 видам трибы. 3) Будет проведен филогенетический анализ по конкатенированному набору нескольких пластидных маркеров группы Lotus angustissimus. 4) Будет опубликована одна статья по теме проекта.

1. ФИЛОГЕНЕТИЧЕСКИЕ ИССЛЕДОВАНИЯ БОБОВЫХ. Филогенетический анализ родов Lotus и Anthyllis по ITS и ETS ядерной ДНК и пластидным маркерам показал неконгруэнтность пластидных и ядерных деревьев и подтвердил монофилию родов Lotus (вкл. Tetragonolobus и Dorycnium) и Anthyllis (вкл. Hymenocarpos) (Degtjareva et al., 2006, 2008, 2012; Kramina et al., 2016). NrITS и хлоропластные маркеры показали, что монотипный род Podolotus – ближайший родственник рода Coronilla (Degtjareva et al., 2010). Показана таксономическая значимость инделей в участке trnF-trnL хпДНК в секции Lotus (Kramina et al., 2018). Подтвержден немонофилетический характер секции Bonjeanea рода Lotus. Оценен предполагаемый возраст дивергенции видов секции (4,16-6,1 млн. лет) и рода Lotus (ок. 15,87 млн. лет назад) (Kramina et al., 2021). Пластидные данные показали низкое разрешение между секциями Dorycnium и Bonjeanea (Kramina et al., 2022). 2. ОПЫТ ИЗУЧЕНИЯ ПЛАСТОМОВ. Получены 11 полных пластомов трибы Tordylieae зонтичных и сопоставлены с пластомами родственных таксонов. Пластомы варьируют в пределах 141,148-150,103 п.о. и включают 122-127 генов, из которых 79-82 кодируют белки, 35-37 кодируют тРНК, 8 - рРНК. Выявлены значительные различия в длине инвертированных повторов (IRs) и составе генов, сопровождающиеся экспансией IR на границе LSC (Large Single-Copy region) / IRa (Samigullin et al., 2021). Присутствие псевдогена psbA в IR около границы LSC может представлять кладо-специфичную синапоморфию в трибе Tordylieae (Samigullin et al., 2022). Получены полные пластомы для других групп растений: пиона Paeonia lactiflora, с потерей генов rpl32 и infA (Samigullin et al., 2018a); бобового Carmichaelia australis, с потерей гена rps16, интрона rps12 и первого интрона clpP (Samigullin et al., 2018b); голопаразитических (Lathraea squamaria) и микогетеротрофных (Petrosavia stellaris) растений со значительной редукцией пластома в связи с особенностями их питания (Samigullin et al., 2016; Logacheva et al., 2014).